Not Applicable.
Not Applicable.
1. Field of the Invention
The present invention is directed to a device that can be made smaller and with improved electrical characteristics than prior art devices and, more particularly, to a semiconductor device that can be made with a package that allows for greater device densities on circuit boards, shorter lead lengths, more tolerance to non-uniformities, and improved cooling.
2. Description of the Background
Electronic products typically contain a large number of electrical devices organized on one or more substrates, also known as circuit boards. The efficient packaging of those devices is an important factor in the product""s performance. One way to improve performance is to increase the density of electrical devices on the substrate. For example, density may be increased by decreasing the size of the devices, thereby increasing the number of devices that can be placed on a given substrate.
One way to increase device density is to use vertical packaging, which places devices perpendicular to the substrate. Vertical packaging allows for many more devices to be placed on a substrate because vertically oriented devices have smaller footprints than horizontally oriented devices. However, vertical packaging is subject to package instability (i.e. tipping over), particularly during processing steps involving poor adhesion between the device and the substrate, such as solder reflow. That instability is caused, in part, by non-uniformities in both the substrate and device. As a result, vertical packaging requires additional steps to create more uniform devices and substrates, and to stabilize the devices during some processing steps.
Conventional devices and substrates also suffer from other problems caused by non-uniformities. For example, bending of device leads and poor contact between the device and substrate may result if the device and substrate are not uniform. Such problems require that device leads be lengthened to allow for greater flexibility to compensate for the non-uniformities. Longer leads, however, may result in the lead bending and possibly creating a short between conductors on the substrate. In addition, longer leads may cause detrimental electrical characteristics, such as increased resistance, increased capacitance, and decreased speed. Furthermore, longer leads tend to increase instability problems when there is poor adhesion between the device and the substrate.
Thus, a need exists for an improved device to allow for increased device densities without the deficiencies of the prior art.
The present invention is direct to a device comprising a circuit, a lead having a first end connected to the circuit and having a second end, and a deformable structure connected to the second end of the lead. The invention may be embodied on a circuit board, so that the circuit board includes a substrate and a deformable structure connected to said substrate.
The present invention is also directed to a device comprising a circuit having an active side and a non-active side, a package enclosing the active side of the circuit and not enclosing a portion of the non-active side of the circuit, and a lead having a first end connected to the active side of the circuit via a lead-over-chip connection, and having a second end extending from the package.
The present invention is also directed to a device comprising a circuit and a lead formed from a flexible conductor, with the lead having a first end connected to the circuit.
The present invention solves the shortcomings of the prior art by providing for higher device densities, shorter lead lengths, and more tolerance of non-uniformities, such as those in devices and substrates. Those and other advantages and benefits of the present invention will become apparent from the description of the invention provided hereinbelow.